Artificial Neural Network for Modeling the Tensile Properties of Ferrite-Pearlite Steels: Relative Importance of Alloying Elements and Microstructural Factors

Tae‑Woon Hong,Sang‑In Lee,Jae‑Hyeok Shim,Myoung‑Gyu Lee,Joonho Lee,Byoungchul Hwang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

An artificial neural network (ANN) model was developed to predict the tensile properties as a function of alloying elementand microstructural factor of ferrite-pearlite steels. The input parameters of the model were composed of alloying elements(Mn, Si, Al, Nb, Ti, and V) and microstructural factors (pearlite fraction, ferrite grain size, interlamellar spacing, and cementitethickness), while the output parameters of the model were yield strength and tensile strength. Although the ferrite-pearlitesteels have complex relationships among the alloying elements, microstructural factors, and tensile properties, the ANNmodel predictions were found to be more accurate with experimental results than the existing equation model. In the presentstudy the individual effect of input parameters on the tensile properties was quantitatively estimated with the help of theaverage index of the relative importance for alloying elements as well as microstructural factors. The ANN model attemptedfrom the metallurgical points of view is expected to be useful for designing new steels having required mechanical properties.

600W급 IPMSM의 구동특성 변화에 따른 온도 내력 분석

이원식(Wonsik_Lee),고덕화(Duk-Hwa Go),김용태(Yong-Tae Kim),조규원(Gyu-Won Cho),김규탁(Gyu Tak Kim) 대한전기학회 2016 대한전기학회 학술대회 논문집 Vol.2016 No.10

본 논문에서는 동일 출력에서 연기전력 증가 및 형상 변경을 통한 효율 향상 전동기와 기본모델 전동기를 열 등가회로망법을 사용한 열해석을 수행하여 온도 내력을 비교, 분석하였다.

부신피질 자극호르몬 단독결핍 1례

박경식,이승현,최석영,박태규,이동화,이찬우,정성복,이인규 啓明大學校 醫科大學 1997 계명의대학술지 Vol.16 No.3

부신피질 자극호르몬 단독결핍은 국내에서 7례만이 보고된 희귀 질환이며 병인 및 경과 등 아직 불분명한 측면이 많다. 이는 질환지체의 희귀성도 있지만 치료후 자연경과에 대한 장기적인 추적검사가 이루어진 경우가 드물기 때문이기도 하다. 저자들은 비특이적인 전신증상을 주소로 내원한 폐경기후의 56세 여자 환자에서 자가면역질환의 증거없이 고프로릭틴혈증을 보인 부신피질 자극호르몬 단독결핍 1례를 경험하고 1년간의 부신피질호르몬 대치요법후 추적검사를 실시하였기에 문헌 고찰과 함께 보고하는 바이다. Isolated ACTH deficiency is a rare disorder which shows secondary adrenal insufficiency with normal states of other pituitary hormones. A 56-year-old postmenopausal woman complaining general weakness and intermittent mental confusion presented negligible serum cortisol and ACTH level with hyperprolactinemia and mild hyponatremia. Rapid ACTH stimulation test did not show significant increase of serum cortisol level. Combined pituitary stimulation test showed negligible response of cortisol and ACTH, and slightly decreased response of prolactin and gonadotropin. But the responses of TSH and GH were normal. There was no evidence of organic pituitary of hypothalamic lesion in brain MRI and antithyroid autoantibody was not detected in serum. After receiving 12 months of glucocorticoid replacement therapy, she skipped the medicine for 3 weeks and we performed follow-up endocrinologic tests. Serum ACTH and cortisol level was also negligible and prolonged ACTH simulation test showed normal response of serum cortisol. CRF stimulation test showed no response of serum ACTH. Basal prolactin level was decreased to near normal and combined pituitary stimulation test showed normal response of prolactin with slightly blunted response of TSH and GH. We concluded that the case was nonautoimmune origined isolated ACTH deficiency which was accompanied by hyperprolactinemia and resultant deficiency of gonadotropin, so we report this case with review of literatures.

국제분쟁의 평화적 해결수단에 관한 연구

이태규 안양대학교 1997 논문집 Vol.17 No.-

國際紛爭은 이제 더 이상 당해 紛爭當事國들이 자의적인 힘의 논리로 武力의 행사와 그 위협 또는 침략행위로써 해결되는 대상이 아니다. 점점 커온 人類理性을 바탕으로 제 1 차 세계 대전 이후부터 일기 시작한 戰爭과 武力行使의 國際法的 規制의 노력은 유엔 憲章에 그 결정체가 담겨져 있다. 이러한 國際紛爭의 平和的 解決原則을 구체화하는 방법과 수단은 UN 헌장 제 33 조에 나열되어 있듯이 외교적 交涉, 周旋, 사실문제에 관한 審査, 仲介, 調停, 仲裁, 司法裁判, 地域的 해결기구의 이용 등으로 나뉘어진다. 특히 요즈음 들어 독립된 국제기관에 분쟁의 해결을 맡기는 경향이 대두됨에 따라 仲裁裁判이나 國際司法裁判의 중요성이 더욱 증대된다.섀??I[

조합법을 사용한 철근콘크리트 골조의 비선형 해석

이태규 우송대학교 2000 우송대학교 논문집 Vol.5 No.-

The entire nonlinear behavior of reinforced concrete frames up to collapse, is analyzed by the displacement control method and the combined layered and nonlayered method. All of the rigidities of section are calculated approximately by a sum over all the layers for the layered method, are used the integral values over the cross section area for the nonlayered method. The spurious sensitivity to the chosen element size in the result of analysis by finite element method for the materials with strain-softening can be overcome by modifying the strain distribution based on the concept of fracture energy at plastic hinge considering the applied axial load.

財務管理의 目標 및 體系에 관한 硏究

李泰奎 충남대학교 경상대학부설 경영경제연구소 1984 경영논집 Vol.6 No.2

굽힘모우멘트를 받는 혼합형모드의 외부크랙에 대한 응력확대계수

이치우,김태규 慶南大學校 附設 工業技術硏究所 1986 硏究論文集 Vol.4 No.-

파괴역학에서 크랙첨단부근의 응력분포는 응력확대계수로 표시함은 잘 알려진 사실이다. 임의의 경사각을 가지는 혼합형모드(Mixed Mode)에 대해서 외부직선크랙, 반원형외부크랙, 외부노치크랙을 갖는 판이 순수굽힘, 3점굽힘, 등분포하중을 받는 경우에 대한 해석을 광탄성적인 방법(Photoelastic Method)으로써 응력확대계수를 결정하였다.. 특히 외부직선크랙을 가진 판이 개구형모드(Opening Mode) 상태에서 순수굽힘 및 3점굽힘을 받을때의 결과는 Gross, Srawley, Wilson 등이 연구한 경계분할법(Boundary Collocation Method)과 잘 일치함을 관찰할 수 있었다. The stress distribution in the vicinty of the crack tip in Fracture Mechanics ordinary indicated by stress intensity factors K which have been Proposed by Irwin. In the analysis of stress intensity factors, there are many theoretical and experimental method. This paper was stuided for stress intensity factors of a steet with inclined crack of a subjected to pure bending moment, 3-points bending moment and Uniform distributed load by photoelastic method. The results of this method, the stress intensity factors subjected to pure bending moment and 3-points bending moment were very coincided result of the Gross and Srawley by Boundary Collocation method.

호기성 생물막 여과법을 이용한 제지산업 폐수의 처리 특성

이태진,오중교,이용택,정두식 경희대학교 환경연구소 1995 環境硏究 論文集 Vol.6 No.-

This work researched the treatment characterization of paper mill waste water for Biological Aerated Filter (BAF)system. BAF process is ideal for reclamation and reuse of wastewater. It features excellent removal of organic matter and SS, Especially. it is easy maintain and achieves energe-saving and space-conservation when compared to conventionnal activated sludge method. This study resulted that upflow BAF system showed superior treatment efficiency to downflow one. The removal efficiencies of BOD, COD, SS were 85%, 80, 90%, respectively.

Cone beam형 전산화단층촬영에 의한 흡수선량

이의태,김규태,최용석,황의환 대한구강악안면방사선학회 2007 Imaging Science in Dentistry Vol.37 No.2

Purpose : To measure the absorbed doses of cone beam computed tomography (CBCT), which is recently being more frequently used, and to compare them with those of panoramic radiography. Materials and Methods : To measure the absorbed doses of CBCT (PSR-9000N, Asahi Roentgen Ind. Co., Japan), we placed TLD chips on the skin regions above the parotid and thyroid glands, and on the dorsum of tongue in a dental head phantom. We used two image acquisition modes of the Dental and Panoramic modes of CBCT, which differed in the field of view. Also, panoramic radiographs (Auto IIIN, Asahi Roentgen Ind. Co., Japan) were taken to compare with the absorbed doses of CBCT. Result : In the Dental mode of CBCT, the absorbed doses of the parotid gland, dorsum of tongue, and thyroid gland were 3.53, 3.13, and 0.36 mGy, respectively. In the Panoramic mode of CBCT, they were 9.57, 9.15, and 0.85 mGy, respectively. The panoramic mode showed higher absorbed doses than those of the Dental mode. In the panoramic radiography, the absorbed doses of the parotid gland, dorsum of tongue, and thyroid gland were 1.21, 1.19, and 0.16 mGy, respectively. And they were about 1/3 of the Dental mode and 1/9 of the Panoramic mode of CBCT. Conclusion : Absorbed doses of CBCT are higher than those of panoramic radiography, and dependent upon the field of view.

기관지 방선균증의 임상 1례

이은영,장태원,정만홍,옥철호,이규원,손창배,이지숙,신은경,서정아,백종현,김영옥 고신대학교의과대학 2007 고신대학교 의과대학 학술지 Vol.22 No.2

Actinomycosis is a chronic suppurative infection, whitch infiltrates mucosa-associated tissues. Thoracic, pelvic and cervicofacial infections of actinomyces are not uncommon, but endobronchial actinomycosis is rarely reported. We report a case of a 29 year old man who presented with a recurrent pneumonia and chronic cough. Fiberoptic bronchoscopy revealed occlusion of the right. lower medio-basal segment bronchus with exophytic endobronchial mass. The diagnosis was confirmed histologically by demonstration of sulfur granules in the bronchoscopic biopsy of the mass. Intravenous administration of amoxacillin and clindamycin followed by oral amoxacillin and clindamycin therapy resulted in complete recovery.